A few years into her marriage, Hibiki has been trying her best to be a "good wife" to her husband, but the distance between them keeps growing, and she is worried about how to get her life back to normal. One day, Hibiki meets Aoi, the husband of a friend who lives nearby. As they talk about their troubles, the two of them grow closer, and they end up committing adultery for the first time in their lives. However, Hibiki does not realize that the price of her first infidelity after marriage will be so high...